Do Not Touch

Synonyms / Other Terms Used

No Touching, No Touch

Category

Regulations, Management, Safety, Prohibition, Prohibited Actions, Prohibition Symbols

Message / Function

To prohibit touching objects or parts of an object
To indicate a surface that must not be touched

	Source	Description
A)	SCC	Circle with diagonal negation bar in front of side view of finger tip close to horizontal line
B)	Olgyay	Circle with diagonal negation bar in front of hand with outstretched index finger pointing towards tilted bar
	Brady 1978	Circle with diagonal negation bar in front of hand with two outstretched fingers near horizontal bar
C)	Collins 1983	Circle with diagonal negation bar, hand with outstretched index finger pointing downwards towards horizontal bar
	safetysign.com	Circle with diagonal negation bar in front of hand with outstretched index finger pointing downwards near horizontal bar with rectangular element
D)	Parks Canada	Circle with diagonal negation bar, hand with outstretched index finger pointing downwards towards horizontal bar
	Dreyfuss	Hand with outstretched index finger pointing downwards towards horizontal bar, diagonal negation bar behind
	Kapitzki	Diagonal negation bar in front of hand in outline, with outstretched index finger pointing downwards towards horizontal bar
	ISO 7010	Circle with diagonal negation bar in front of side view of hand and horizontal line underneath
E)	ANSI Z535.3 1991	Diagonal negation bar in front of hand grabbing rectangular object
	TFSB	Diagonal negation bar in front of plan view of hand near jagged element
F)	CNIS	Diagonal negation bar in front of plan view of hand near horizontal bar above
	Banner House	Circle with diagonal negation bar in front of plan view of hand
G)	Eco-Mo Foundation	Circle with diagonal negation bar in front of plan view of hand
	EJP	Plan view of hand, diagonal negation bar
	SS	Diagonal negation bar in front of plan view of hand turned by 45°
	monotaro	Diagonal negation bar in front of plan view of hand turned by 45°
	X'70	Plan view of hand with fingers showing downwards, crossed out
	Vecteezy	Circle with diagonal negation bar in front of plan view of hand with fingers spread
	Seton	Circle with diagonal negation bar, side view of cuff and hand with an outstretched finger behind
	Seton	Circle with diagonal negation bar in front of side view of hand including wrist, with an outstretched finger
	Aicher OAP	Diagonal negation bar in front of plan view of hand with outstretched index finger pointing downwards

Note: Some of the examples shown above were mirrored horizontally to contrast differences.

Discussion

The examples shown above are only a small selection from the wide range of pictograms and symbols for the referent Do Not Touch resp. No Touching, that can be found in publications and guiding systems worldwide. There are several general concepts and a multitude of visualizations. It seems there is no real single stereotype to express this message. In such a case often no satisfying solution with good comprehensibility can be determined. Moreover some of the variants in use are very similar to solutions used for the message No Entry, Keep Out and therefore increasing the complexity of this situation.

Research data in our database regarding comprehensibility of symbols for this referent is available from various locations and covers several, but not all concepts:

When Collins (1983) examined the graphical symbols marked A) and C) on basis of a multiple choice test for comprehensibility, conducted mainly among blue collar industrial workers, pictogram A) reached 95.5 % and C) 89.6 % correct answers, but all three distractors (Do not lift objects manually, Wear protective shoes and First aid location) were completely unreasonable. This again is an example for distorted results arising from insufficient quality of distractors in multiple choice based testing, making conclusions from this study questionable. Also Wolff & Wogalter (1998) regarded the variant marked A) in their study. In an open ended Comprehension Test without context information 67 % of the responses were classified as correct, compared to 78 % with context information. In a multiple choice test for comprehensibility this variant reached 79 % correct with plausible distractors versus 90 % and 93 % with less plausible distractors.

Evaluating the Parks Canada’s National Park and National Historic Sites symbols, also prohibition symbols were examined using a Comprehension Test according to ISO 9186. Reporting the results regarding Prohibition Symbol No 1-1-043: Do not touch, which is a slightly improved variant of the pictogram marked C) examined by Collins (1983), the authors stated: 'This symbol brought forth the highest level of “don’t know” responses among all of the prohibition symbols (50%). The remaining responses for this symbol were fairly evenly split between acceptable (27%) and unacceptable responses (24%). There was a wide range of unacceptable responses including “do not go down” (3%), “don’t push the button” (2%), “do not put finger here” (2%), “do not point” (2%), and “no garbage dumping here” (2%)' (Ipsos-Reid Corporation, 2003, page 28).

Data for the pictogram variant marked with B) and labeled Olgyay, showing a circle with diagonal negation bar in front of a side view of a hand with outstretched index finger pointing towards tilted bar, reveals satisfactory comprehensibility with 90 % correct answers (Olgyay, 1996). 'Don't put your finger into it' and 'Be careful when you push the safety button' were among the few wrong answers recorded.

In a paper regarding comprehensibility of safety symbols from the standard ANSI Z535.3 standard published in 1991, Deppa & Kalsher (2006) also present data for the variant marked E) in the table above. With 51 % of the responses classified as correct, comprehension of this pictogram was relatively poor. No details about the most relevant wrong responses were presented that could be regarded for improving this design.

Data regarding safety signs available from the Eco-Mo Foundation (2001) again is based on a multiple choice format with only four possible choices. The pictogram labeled Eco-Mo Foundation and marked G), which is identical to the variant standardized in Japan, reached a score 88.2 in that study. No information is available about the distractors employed.

In more recent research by Hung & Tan (2024) the pictogram labeled CNIS and marked F), but presented inside a red circle, was part of the material used to study factors of sign comprehension. With a comprehension score of 64.62 % this variant seems to be far from well comprehensible among the sixty-five students who participated in this study. Its level of comprehension was classified as Medium.

Recommendations

Due to the fact that data from research does not cover the whole range of image contents available and test results differ to a large extent between the studies presented, also due to various factors like inconsistent color coding, test settings, methodological deficiencies, etc., we recommend some additional testing using the Comprehensibility Estimation procedure for eliminating poor variants and identifying the best of the set available, followed by a Comprehension Test. These studies should deliver useful data for recommending the best pictogram. Detailed information about the most frequent responses given in each of the response categories of the Comprehension Test should be provided to correctly judge comprehensibility and improve designs.

Before starting further research, we advocate designing some new pictogram variants, considering a more natural orientation of the hand, employing motion lines to indicate movement, and/or aspects regarding the object being touched, like a dent at the point of contact. Such changes possibly might improve comprehensibility.

Tests of pictograms of referent DoNotTouch

Collins, B.L. (1983): Use of Hazard Pictorials/Symbols in the Mineral Industry. Washington, D.C.: National Bureau of Standards, NBSIR 83-2732, September 1983.

Deppa, S.W. & Kalsher, M.J. (2006): Safety Symbols in ANSI and ISO Voluntary Standards - Do People Understand them? Proceedings of the Human Factors and Ergonomics Society Annual Meeting. 50. 2192-2194. 10.1177/154193120605001901.

Eco-Mo Foundation (2001): Test data of public information symbols in Japan - Procedure for the testing of public information symbols by the Study Committee. ISO: ISO/TC 145/SC 1 N 329.

Hung Y-H & Tan Y. (2024): How symbol and text combine to promote sign comprehension: Evidence from eye-tracking. Displays. 83, 102709. https://doi.org/10.1016/j.displa.2024.102709

Ipsos-Reid Corporation (2003): Evaluation of Parks Canada’s National Park and National Historic Sites Symbols – Phase I.

Kudo, M. (2022): Graphic Design of Pictograms Focusing on the Comprehension of People with Intellectual Disabilities – The Next Step in Standardization: Pictogram Design and Evaluation Methods. Visible Language. 56 (3), pp.58-85.

Olgyay, N. (1996): Safety Symbols Art: The Testing Protocol, Materials & Results. Foci Studio, Washington, DC.

Wolff, J.S. & Wogalter, M.S. (1998): Comprehension of Pictorial Symbols: Effects of Context and Test Method. Human Factors 40 (2), 173-186.